Fastener device



Jan. 22, 1963 c. J. DE CARO 3,074,071

FASTENER DEVICE Original Filed June 18, 1958 2 Sheets-Sheet 1 5 5 7 IN V EN TOR.

CHARLES J. DECARO A TTORNEY C. J. DE CARO FASTENER DEVICE Jan. 22, 1963 2 Sheets-Sheet 2 Original Filed June 18, 1958 FIG? Has zQ INVENTOR. CHARLES J. DECARO BY Arr omvgr United States Patent 3,074,071 FASTENER DEVICE Charles J. De Caro, Brecksville, Ohio, assignor to 01in Mathieson Chemical Corporation, East Alton, 11]., a corporation of Virginia Original application June 18, 1958, Ser. No. 742,874, now Patent No. 3,040,326, dated June 26, 1962. Divided and this application Dec. 11, 1961, Ser. No. 165,054 2 Claims. (Cl. 144.5)

This invention relates to tools and more specifically to explosive operated tools. This application is a division of copending patent application Serial No. 742,874 filed June 18, 1958, now Patent No. 3,040,326, issued June 26, 1962.

One type of such tool includes either a work impacting, piston or a tool-carrying ram driven at high velocity. Explosive tools of this type utilizing blank cartridges are shown in U.S. Patents 1,466,968 (Smith); 2,008,362 (Littlehale) and 2,221,157 (Temple). Heretofore many of these have included some additional structure to mollify the impact of the piston, the stopping of which without breaking of part of the tool presents a problem encountered in this art. The problem is particularly serious in those instances where inadvertently no part to be worked on is emplaced in the tool so that the piston collides with full force against the piston stop at the muzzle of the tool barrel, and also in those instances where the resistance offered by the piece worked upon or driven into varies from piece to piece or from area to area. Heretofore used shock absorbers, such as air chambers and rubber buffers have the disadvantage of either requiring entirely to close a tolerance and/or suffering impairment under the heavy blow and high temperatures encountered. Some violently recoil the piston.

Therefore, one object of this invention is to provide an explosive actuated tool having new and improved shock absorbing means overcoming the foregoing and other objections encountered in prior art devices of this type. Another object is to provide a new and improved apparatus operated by a blank cartridge for driving a punch or a ram with high force and velocity down the bore of a barrel. Still another object is to provide in explosive actuated punching tools a built-in shock absorbing structure for cushioning any collision which may occur between the tool parts. The foregoing and other objects of this invention are accomplished in accordance with this invention by the provision of a new and improved barrel structure.

Specifically, it has been found that lamination or subdivision of the barrel in the manner and relationship described herein results in very high resistance of the barrel to breakage in the event that the tool carrying piston or ram strikes the piston retaining stop at the muzzle of the barrel.

The laminations may take various forms. They may take the form of a closely wound helical coil or spiral segments with quadrilateral or D-shaped cross sectional turns in contiguity with each other. They may take the form of arcuate wedge-shaped segments extending longitudinally and laid up side-by-side to extend circumferentially over 360 and to complete the barrel. Another form is that of a bundle of strands such as wires of a suitable metal such as steel. Still another form effectively increases the length of the barrel and more particularly consists of a coaxial arrangement of relatively thin tubes interconnected at the ends so as to transmit and effectively absorb impact of the piston.

The invention is better understood from the following description of various preferred specific embodiments and the accompanying drawing of the same wherein:

A 3,074,071 Patented Jan. 22, 1963 FIGURE 1 is a longitudinal cross sectional view illustrating one preferred embodiment;

FIGURE 2 is a longitudinal view showing a second embodiment;

FIGURE 3 is a transverse cross sectional view taken on line III-HI of FIGURE 2;

FIGURE 4 is a transverse cross sectional view taken looking up the barrel bore toward the breech with the piston removed and illustrating another embodiment;

FIGURE 5 is a transverse cross sectional view taken through the piston stopping member looking toward the muzzle of the embodiment of FIGURE 4;

FIGURE 6 is a longitudinal cross sectional view illustrating a still further embodiment; and

FIGURE 7 is a longitudinal view in cross section showing further details of the embodiment of FIGURES 4 and 5.

In the embodiment of FIGURE 1, the tool comprises a piston 1 slidably mounted in the barrel bore 10 wherein it may be driven forcibly from the initial position shown by explosion of the powder cartridge 5 until the working element, such as the punch 2 carried by the piston is projected through the opening 7 of the piston abutment sleeve 6 at the muzzle of the tool barrel to drive fastener F into support S.

The barrel comprises the helical coil, preferably a tension spring 3 having turns of heavy quadrilateral cross section, either rectangular, square or parallelogramic, with adjacent turns normally closely fitting against each other to make a barrel with closed side walls at least adjacent the breech plug 4 having a chamber for receiving the cartridge 5. The coiled barrel 3 is joined at its ends to the plug 4 and sleeve 6 by any suitable means such as threads 8 and 9, respectively.

The barrel may consist of a D-shaped coil or of a double or triple lead coil made in any suitable way as by helically slotting a cylinder and twisting it to close up the slots. Whatever coil form is used should provide the relatively smooth and continuous barrel bore 10 for piston 1.

In the form of the invention shown in FIGURES 2 and 3, the tool includes piston 11, its working element 12, the longitudinally extending barrel segments 13, and the barrel collar 14. Element 12 may be a. punch for workpiece W.

The segments preferably 'take the shape shown to include the piston stopping foot 17 and the breech sector 19. The barrel is assembled by staking the segments 13 in the collar 14 with a force fit. A shouldered portion of each segment and the collar is abutted as at 20 to give positive axial restraint where needed in addition to the frictional retention. Snap-ring 16 locks the assembly having a breech chamber for receiving powder cartridge 15, the smooth closed barrel bore 10 and the piston stopping array of segment ends 17 defining the opening 18 through which element 12 acts upon the work when the piston 11 is driven at high velocity from the initial position shown.

In the embodiment piston 11 has a tapered forepart 31 which collides with the mating taper 30 at the muzzle end of the segments in the event normal working conditions are absent. The action of the taper, particularly at very heavy blows, is to channel energy, in .excess of that absorbable longitudinally in the segments, to dissipate itself in a radially outward elastic deformation of segment 13 and to cause the segments to separate circumferentially momentarily and vent the barrel to exhaust 3 another collar may surround the segment array at the muzzle or over more of the barrel length.

The tool barrel of FIGURES 4 and 5 is characterized by a bundle of rods or wires 23 which form an excellent shock absorbing barrel. At the breech (FIGURE 4) the rods are held between a breech block 21 with a barrel liner 22 and an outer breech collar 24 which may be fixed to the block 21. At the muzzle (FIGURE 5) the rods are held between a piston stopper sleeve 26 having opening 28 for the working punch, and. a muzzle collar 27. This collar may be positively secured to the sleeve 26 by any suitable fastening elements such as studs 29.

The liner 22 is not secured at the muzzle so as not to interfere with the buffering action of the rods.

In the embodiment of FIGURE 6 piston 41 rides in the bore of a barrel of multiple sleeve construction which ettectively increases its length and imparts to it the ability to absorb tremendous shock repeatedly with greatly improved resistance to fracturing.

The barrel consists of a plurality of coaxial tubes such as the inner barrel liner 50, the intermediate tube 53 and the outer tube or sheath 55. At one end the liner 59' is fastened to breech plug 44,carrying cartridge 45, in any .suitable'way such as by welding at 51. At the muzzle Shock forces generated in the event of collision put tubes and in tension and tube 53 in compression. Although three. tubes are shown, five, seven or more may be used. Those in tension are thicker than the other tube laminations.

Since many other embodiments and various modifications of this invention may occur to those skilled in the art, it is to be understood that the foregoing is intended by way of illustration of a preferred embodiment and not as a limitation of the spirit and scope of the present invention except as set forth in the appended claims.

What is claimed is:

1. In an explosive actuated tool having a barrel, a piston received and slidably mounted in the bore of said barrel, means for detonating an explosive charge behind the piston to drive it towards the muzzle end of the barrel with high velocity and force, and a piston retaining means at the muzzle of the barrel, said barrel comprising a closely Wound helical coil'extending longitudinally of the barrel, the adjacent turns of said coil being in contiguity and of cross-sectional shape. such as to present a substantially closed continuous surface on the inside of the coil in the region of said turns to form at least a part of the bore of the barrel, said coil being efiective to increase the shock absorbing capacity of said barrel and its resistance to fracture to cushion the blow whenever the driven piston collides with said retaining means.

2. The tool of claim 1 wherein the coil turns are of quadrilateral cross section.

No references cited. 

1. IN AN EXPLOSIVE ACTUATED TOOL HAVING A BARREL, A PISTON RECEIVED AND SLIDABLY MOUNTED IN THE BORE OF SAID BARREL, MEANS FOR DETONATING AN EXPLOSIVE CHARGE BEHIND THE PISTON TO DRIVE IT TOWARDS THE MUZZLE END OF THE BARREL WITH HIGH VELOCITY AND FORCE, AND A PISTON RETAINING MEANS AT THE MUZZLE OF THE BARREL, SAID BARREL COMPRISING A CLOSELY WOUND HELICAL COIL EXTENDING LONGITUDINALLY OF THE BARREL, THE ADJACENT TURNS OF SAID COIL BEING IN CONTIGUITY AND OF CROSS-SECTIONAL SHAPE SUCH AS TO PRESENT A SUBSTANTIALLY CLOSED CONTINUOUS SURFACE ON THE INSIDE OF THE COIL IN THE REGION OF SAID TURNS TO FORM AT LEAST A PART OF THE BORE OF THE BARREL, SAID COIL BEING EFFECTIVE TO INCREASE THE SHOCK ABSORBING CAPACITY OF SAID BARREL AND ITS RESISTANCE TO FRACTURE TO CUSHION THE BLOW WHENEVER THE DRIVEN PISTON COLLIDES WITH SAID RETAINING MEANS. 